Earthquake Precursors and Controls on Earthquake Magnitudes: Probing the Behavior of Megathrust Faults through Numerical Simulations

GSTDTAP

项目编号	1723249
	Earthquake Precursors and Controls on Earthquake Magnitudes: Probing the Behavior of Megathrust Faults through Numerical Simulations
	Julia Morgan
主持机构	William Marsh Rice University
项目开始年	2017
	2017-08-01
项目结束日期	2019-07-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	205780(USD)
国家	美国
语种	英语
英文摘要	Large or great earthquakes that occur along subduction zones rupture large portions of the fault interfaces, releasing substantial accumulated energy capable of causing catastrophic damage and disruption. As such earthquakes define a major geohazard, particularly to coastal areas vulnerable to large tsunami, understanding the controls on earthquake size and the predictors of their occurrence along megathrust faults is of critical societal relevance to the US and around the world. This project will provide new insights into how and why earthquakes occur on these major faults, and what determines how large they can become. We will use numerical modeling to simulate the conditions present in such settings, to predict fault behavior. Earthquakes are of great popular interest, and our models of virtual earthquakes will provide a stimulating way to inform the public about natural processes and their effects. We will prepare and distribute animations of our earthquake simulations and related phenomena by way of a webpage, and communicate our science through collaborative arrangements with local schools and Rice teacher training courses. We will also develop new course materials that can be used in undergraduate geology courses. In this study, we will carry out a systematic modeling study using particle dynamics simulations to examine the controls on seismic and aseismic slip on numerical analogs of heterogeneous faults modeled after subduction megathrusts. Consistent with subduction megathrusts, our research will focus on asymmetric faults in which stress and strength vary along the length of the fault. We will use these simulations to develop catalogs of slip events in both 2D and 3D, and then probe conditions along the fault before, during, and after the events to gain insights into the conditions that initiate unstable sliding, and those that cause run-away slip to stop. The overarching questions we plan to address are: (1) What controls the size of an earthquake? Is earthquake size predetermined, and if so, by what? (2) Are there any consistent precursory phenomena (e.g., deformation) or properties changes that can inform us about the onset of seismic slip? To address these questions, we will probe the model data, including particle displacements, forces, packing arrangements, etc., to obtain direct constraints on stress and strains and their variations in space and time, as well as evolving mechanical properties such as friction, dilatancy, strength, and stiffness. In this way, we can explore specific controls on earthquake rupture and other slip behaviors. We will also compare our catalogs of simulated earthquakes, correlated with the properties changes listed above, with natural systems. Our models will help to clarify the characteristics of faults responsible for different types of earthquakes, and the processes that initiate and limit them, advancing our knowledge in this area. This project will support one graduate student and one undergraduate student, and formalize interdisciplinary collaborations at Rice. We will publish and present our results at national and international meetings.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/71399
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Julia Morgan.Earthquake Precursors and Controls on Earthquake Magnitudes: Probing the Behavior of Megathrust Faults through Numerical Simulations.2017.